1. Field of the Invention
The present invention relates to a container for holding an article such as food and, more particularly, to a container which is easy to open.
2. Description of the Prior Art
Metal cans with pull-tabs are preferred for use in automatic vending machines of soft drinks or the like. This is because metal cans are easy to open and allow retort sterilization. However, a metal can with a pull-tab requires more parts than a simple metal can, such as a pull-tab and a rivet for mounting it. Furthermore, a notch-shaped or thin cutting guide must be formed to allow opening of a lid along a predetermined shape upon pulling the tab. Metal cans are heavy in weight and are inconvenient to transport. There is also the problem of where to discard the empty cans.
For these reasons, paper or synthetic resin containers for holding soft drinks or food have been proposed. These containers are light in weight, easy to transport, and allow easy disposal after use. It is proposed to mount a pull-tab for a container of this type as in the case of a metal can. However, at least that part of the lid which is to be opened when the pull-tab is pulled must be made of a synthetic resin material, and this results in poor gas barrier properties. Paper containers cannot be subjected to retort sterilization.
Another container has also been proposed which is prepared by forming a hermetically-sealed and heat-resistant container element from a laminate of synthetic resin films, a synthetic resin film and a paper sheet, a synthetic resin film and an aluminum foil layer, a paper sheet and an aluminum foil layer, and so on; filling the container element with desired contents; and sealing the opening of the container element with a lid consisting of an aluminum foil layer or the like.
The container of this type requires the use of a knife or the like to cut the lid in order to open it. In order to solve this problem, it has also been proposed to form a hole in the lid in advance and to seal a piece of an aluminum foil tape with a pull-tab to this hole. However, with this container, the cut portion tends to form irregular sharp edges and may thus hurt lips or hands of the user.